public class TestDemo {
    public static void main(String[] args) {
        /*课堂练习1 抽象类练习 画板类DrawingBoard
        work1.Rectangle rectangle = new work1.Rectangle(10.0,5.0,"红色",false);
        work1.Circle circle = new work1.Circle(3.0,"绿色",true);
        work1.Square square = new work1.Square(4.0,"黄色",false);
        System.out.println(rectangle.toString());
        System.out.println(circle.toString());
        System.out.println(square.toString());
         */
        /*多态
            接口名 变量名 = new 实现类();
         */
    }
}